JPH04261757A - Machining dimension correcting device - Google Patents

Abstract

PURPOSE:To suppress the generation of off-specification machined articles to a minimum by forming a machining measure correcting device in such a way as to measure the machined measure of a workpiece to perform correction in the carry-in-out process of the workpiece to/from a machine tool. CONSTITUTION:A carrier for carrying a workpiece W out of 5 machine tool is provided with a positioning base 25 for positioning/holding the workpiece W in cooperation with clamping claws 18, and the clamping claw 18 is provided with a measuring arm 26 having a measuring terminal 28 brought into contact with the periphery of the workpiece W interlockingly with the clamping claw 18. A detector 30 is provided to electrically detect the displacement quantity of the measuring arm 26. The signal of this detector 30 is inputted into an amplifier 31 built in an unloader 15 to detect the outer diameter dimension of the workpiece W. The measured result is taken into a CPU in a control device so as to determine the correction quantity, and a correction signal is sent out to the control device of the machine tool to correct the machining dimension.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for correcting the dimensions of a workpiece machined by a processing machine.

0002

[Prior Art] Conventionally, in order to correct the machining dimensions of a workpiece processed by a processing machine, as shown in FIG. A measuring machine 3 is installed at a location, the measuring machine 3 measures the machining dimensions of the workpiece W, processes the data, and sends a correction signal to the machining machine 2 in the previous process when the machining dimension deviates from the target value and requires correction. Alternatively, as shown in FIG. 7, a measuring station 7 is installed at one end of a transfer machine 5 having a plurality of processing stations 6, and a measuring machine in this measuring station 7 measures the workpiece W. A method is mainly adopted in which the machining dimensions are measured and data processed, and when the machining dimensions deviate from the target value and correction is necessary, a correction signal is sent to the processing machine in the machining station 7 that is executing the machining of that part. It had been. According to these methods, in any case, the measurement results can be fed back to the processing machine to keep the processing dimensions within target values, and the occurrence of defective products can be suppressed as much as possible.

0003

By the way, in normal line production, the processing speed of the processing machine 2 tends to increase more and more, or the number of processing stations 7 tends to increase more and more from the viewpoint of productivity. For this reason, in the method described above, in which a measuring device is simply installed on the transport line 1 and a correction signal is fed back to the processing machine, multiple workpieces W that have already been processed are kept on the transport line until the processing dimensions are actually corrected. 1, and there was a problem that an increase in the number of defective products was unavoidable. Furthermore, since a special measuring device (measuring station) must be installed in the middle of the conveyance line 1 (FIG. 6) or inside the processing machine (FIG. 7), there is also the problem that the space of the processing line inevitably increases.

[0004] In order to avoid an increase in the number of defective products, for example, in Japanese Patent Laid-Open No. 64-92050, a correction boundary value is set within the dimensional tolerance, and a plurality of workpieces are consecutively placed within this correction boundary value. A technique is described for preventing the occurrence of processing defects by outputting a correction signal when the machining process is performed. However, in this case as well, a special measuring device (measuring station) must be incorporated into the processing machine, which inevitably increases the space of the processing line.

The present invention was made to solve the above-mentioned conventional problems, and its purpose is to minimize the occurrence of defective products and to greatly reduce the space on the processing line. It is an object of the present invention to provide a processing dimension correction device with a simple structure.

[0006]

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a transport machine for loading and unloading workpieces into and out of a processing machine.
A positioning table for positioning and holding a workpiece in cooperation with a clamp claw that can be opened and closed, and a measuring means for measuring machining dimensions of the positioned workpiece, and a correction amount is determined based on a signal from the measuring means. The present invention is characterized in that a control means for sending a correction signal to the processing machine is provided.

[0007]

[Operation] In the machining dimension correction device configured as described above, the dimensions of the workpiece can be measured by the measuring means at the same time as the workpiece is held by the conveyor, so the measurement results can be fed forward or fed back to the processing machine. By doing so, the machining dimensions can be corrected immediately. Furthermore, by incorporating the measuring means into the conveyor, there is no need to provide a special measuring station.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples of the present invention will be described below with reference to the accompanying drawings.

In FIGS. 4 and 5, 11 is a workpiece W.
Two processing machines 12 and 13 are arranged on the line of the transport conveyor 11 with appropriate intervals. Further, a guide rail 14 is installed above and parallel to the conveyor 11, and this guide rail 14 is equipped with a loader or unloader 15 for carrying the work W into and out of the two processing machines 12 and 13. hanging, held (
For convenience of explanation, only the unloader that receives the processed workpiece W from one of the processing machines 12 and delivers it onto the conveyor 11 is shown here.

The unloader 15 includes a running section 16 that runs along the guide rail 14, an elevating section 17 that moves up and down relative to the running section 16, and a pair of clamp claws 18 that are provided on the elevating section 17 and that open and close. It is roughly composed of. The unloader 15 is connected to the processing machine 12 as shown in FIG.
The lifting section 17 is lowered above (arrow ■), the processed workpiece W is received from the processing machine 12 by the closing operation (clamping operation) of the pair of clamp claws 18, and then the lifting section 17 is raised (arrow ■). The traveling section 16 travels (arrow ■) to move above the conveyor 11, and at that position, the elevating section 17 lowers again (arrow ■) and the clamp claw 1
The workpiece W is released by the opening operation (unclamping operation) at 8, and is returned to its original position by raising the elevating section 17 again (arrow ■).

As shown in FIGS. 1 and 2, each of the clamp claws 18 of the unloader 15 has its intermediate portion connected to the elevating section 1.
The upper end of the pin 2 is attached to a piston rod 23 extending from a pair of pistons 22 in a cylinder 21 provided in the main body 19.
4 is used to attach the shaft. By supplying and discharging the working fluid into the cylinder 21, the pair of pistons 22 move relative to each other, and in response, the piston rod 23 is operated to extend or contract, and the pair of clamp claws 18 are opened and closed. , the workpiece W is clamped or unclamped at its lower end.

The main body 19 of the elevating section 17 has a V facing downward.
A letter-shaped positioning table 25 is integrally provided, and when the pair of clamp claws 18 performs a clamping operation, the workpiece W is held against this positioning table 25, and the workpiece W is held at a predetermined position. It has become. Further, a recess 18a is formed inside each clamp claw 18, and this recess 18a
A measuring arm 26 is disposed inside, extending vertically. The measuring arm 26 is suspended and held via a parallel spring 27 by a projection 18b of the clamp claw 18 that projects into the recess 18a. A measurement terminal 28 is provided on one side of the lower end of the measurement arm 26, and the measurement terminal 28 is inserted through a cover 29 covering the recess 18a and slightly protrudes from the front surface thereof. The clamp claws 18 come into contact with the outer circumferential surface of the workpiece W in accordance with the clamping operation.

A detector 30 for detecting the amount of displacement of the measuring arm 26 is installed in the clamp claw 18. This detector 30 consists of a core 30b movably housed within a coil 30a, and the tip of the core 30b is joined to the back surface of the measurement arm 26 corresponding to the measurement terminal 28. As a result, when the measurement terminal 28 comes into contact with the outer circumferential surface of the workpiece W according to the clamping operation of the clamp claw 18, the measurement arm 26 is displaced and the position of the core 30b within the coil 30a changes. A predetermined reference voltage is supplied to the coil 30a, so that the core 30b
When the position of the coil 30a changes, the voltage inside the coil 30a changes. The detector 30 is electrically connected to an amplifier 31 built into the main body 19, and changes in the voltage of the coil 30a are detected by the amplifier 31.
It is now entered into The amplifier 31 has a function of determining the diameter of the work W by comparing the voltage of the coil 30a with a reference voltage. One measuring device 32 is configured as shown in FIG. In addition,
In the amplifier 31, the output voltages of the left and right detectors 30 are averaged to obtain the average diameter of the workpiece W.

On the other hand, a control device 36 including an amplifier 33, an A/D converter 34, and a central processing unit (CPU) 35 is installed separately, and the output signal from the amplifier 31 is transmitted to the amplifier in the control device 36. 33 (Figure 3). The control device 36 has a function of determining the correction amount based on the signal from the amplifier 31 and outputting the correction signal to the control device 37 of the processing machine 12.
5, the dimensional intersection of the workpiece W to be processed by the processing machine 12 is set in advance.

In the machining dimension correction device configured as described above, the unloader 15 is positioned above the machining machine 12 at the same time as one of the machining machines 12 finishes machining the workpiece W, and at this position, the elevating section 17 of the unloader 15 is positioned above the machining machine 12. descend. and,
A pair of clamp claws 18 at the descending end of the elevating section 17 performs a clamping operation as the piston rod 23 moves toward the extension side.
As a result, the workpiece W in the processing machine 12 is held by the unloader 15. At this time, the workpiece W is pressed against the positioning table 25 by the clamp claw 18 and held at a predetermined position. On the other hand, in response to the clamping operation of the pair of clamp claws 18, the pair of measurement terminals 28 come into contact with the outer periphery of the positioned workpiece W, the measurement arm 26 is displaced, and the voltage of the detector 30 changes. Then, the amplifier 31 becomes the detector 3
The outer diameter of the workpiece W is measured based on the zero voltage change, and the measurement signal is sent to the control device 36.

The control device 36 converts the measurement signal from the amplifier 31 through the amplifier 33 and the A/D converter 34.
The data is taken into the PU 35 and data processing is performed there. CPU
In step 35, first, the outer diameter dimension grasped from the measurement signal is compared with the dimension tolerance stored in advance, and if the outer diameter is outside the dimension tolerance, the amount of correction in the processing machine 12 is determined, and the correction signal is transmitted. It is sent to the control device 37 of the processing machine 12. The control device 37 of the processing machine 12 corrects the feed amount of the hub based on the correction signal from the control device 36, and prepares for the next processing. However, during this lever, the workpiece W is transferred to the unloader 1.
5, lifting of the elevating part 17, running of the traveling part 16, elevating part 17
is lowered again and transferred onto the conveyor 11 by the unclamping operation of the clamp claw 18, while the loader (not shown)
A new workpiece is carried into the processing machine 12 by the following steps. Therefore, the workpiece can be processed by the processing machine 12 in a predetermined cycle, and productivity is not hindered.

Note that in the above embodiment, the unloader 1
A measuring device 32 was installed in the 5th section, and post-process control was performed using the data obtained by this measuring device 32.
In the present invention, the measuring device may be provided in a loader that carries the workpiece W into the processing machines 12 and 13 to measure the dimensions of the workpiece before processing, and this data may be used to perform so-called preprocess control. . In addition, in the above embodiment, a loader and an unloader are shown as transport machines for loading and unloading the workpiece W into and out of the processing machine, but when a transfer machine (FIG. 5) is targeted, a transfer bar is used as the transport machine. Therefore, in this case, the measuring device 32 is provided on the transfer bar. Further, in the above embodiment, the measuring arm 26 and the detector 30 are provided on the clamp claw 18, but these may be provided on other members that interlock with the clamp claw 18.

[0018]

[Effects of the Invention] As explained in detail above, according to the machining dimension correction device according to the present invention, the machining dimensions of the workpiece can be measured and corrected during the process of loading and unloading the workpiece into the processing machine. As a result, the occurrence of defective products can be minimized. Furthermore, by incorporating the measuring means into the loader or unloader, it is possible to significantly reduce the space on the processing line and to realize an apparatus with a simple structure. Moreover, it can be used not only for post-process control but also for pre-process control, and has great overall effects.

[Brief explanation of the drawing]

FIG. 1 is a partially sectional front view showing the main structure of a processing dimension measuring device according to the present invention.

FIG. 2 is a side view of the processing dimension measuring device shown in FIG. 1.

FIG. 3 is a block diagram showing a signal processing system in the process dimensioning apparatus.

FIG. 4 is a front view schematically showing how the processing dimension measuring device is installed on the processing line.

FIG. 5 is a plan view schematically showing how the processing dimension measuring device is installed on the processing line.

FIG. 6 is a plan view schematically showing how a conventional processing dimension measuring device is installed on a processing line.

FIG. 7 is a plan view schematically showing how a conventional processing dimension measuring device is installed on a processing line. 11 Transfer conveyor 12 Processing machine 13 Processing machine 15 Unloader 18 Clamp claw 25 Positioning stand 26 Measuring arm 28 Measuring terminal 30 Detector 31 Amplifier 32 Measuring device 34 Control device W Work

Claims (1)

[Claims] 1. A conveyance machine for loading and unloading workpieces into and out of a processing machine is provided with a positioning table for positioning and holding the workpiece in cooperation with a clamp claw that can be opened and closed, and a measuring means for measuring the machining dimensions of the positioned workpiece. 1. A processing error correction device comprising: a control means for determining a correction amount based on a signal from said measuring means and sending a correction signal to a processing machine.